NX2 - converting multiple sheets into a single sheet 1

[sebw]

Hi,

I am running NX2 and need to convert multiple sheets into one single sheet that will behave as a single sheet after.

I tried sewing the sheets, but in CAM to create a tool path you can not select the SEW as one single sheet.

Also I tried to subtract / intersect the sheets with a block.

The result remains the same, the solid / sheets do not behave as a single sheet.

Is there a soltuion to this ?

Thanks,

Sebastian

 

[DaSalo]

Final comment: It looks from your JPEG that you have a CAM package that is designed specifically for this application (surfboards). Why not use that? NX can definitly do everything that any other CAM package can but you might have to do some significant customization to get it to behave exactly like a package that is tailor-made for you specific application.

NX 7.5.4, NX 8.0.1.5
Tecnomatix Quality 8.0.1.3
PC-DMIS 2011 MR1

 

[sebw]

Hi DaSalo,

Thanks for the big support here.

I agree that it would be easier to solve it in the CAM. But I could not get it, so I was looking for a different solution.

The JPEG was actually just to show what I want to achieve, I am not using that software - it can not manage any import. I use only the CAM of the NX2.

The toolpath that you got looks like what I want.

I tried to split / divide the surfcace like in your pic (also with more divisions), but I am still getting the same error message on the surface area/drive geometry.

Uprading to NX8 could be an option, but I am a one man show here and that is quite a big investment. If I can find a work around in NX2 it would be better.

 

[DaSalo]

I don't have NX2 so am not going to be able to help you out in any more detail with exactly how to get it to work in that version. My recommendation is to spend some time generating paths with Surface Area using a simplified shape. Remember that Surface Area is looking for even bands of surfaces. Each band (the software calls them "rows") must have the same number of surfaces as every other band. You choose the surfaces in the first row in sequential order, lets say from right to left. Then you click the button that says "select next row". Then you pick the surfaces in the next row in exactly the same order as you picked the surfaces in the first row. Once you have selected the first two rows the software will understand which direction the selection progression is moving in and you do not need to hit the "select next row" button anymore. You do need to continue to choose the surfaces in the same sequential order, one row after another, until you get to the end of the part. This regimented surface selection is absolutely essential for the tool to work correctly.

99% of problems with Surface Area method are due to incorrect sequencing of surface selection. Occasionally you do need to open up the chaining tolerances if you have small gaps between sheets or your surfaces are almost regular, but not quite. You do this in Preferences => Selection. In NX7/8 the setting as at the bottom of the dialogue window and will have a method, which I set to "Simple", and a tolerance, which I set to ~ 1 to 5x my modeling tolerance. On very rare occasions you might need to bump that tolerance up even more. Sometimes it actually works better if you set the tolerance tighter so don't just put something huge in there in an attempt to eliminate the influence of that setting.

Once you have a solid understanding of how "Surface Area" works you will be able to clearly see how the patch layout in your model will fit into this selection scheme. You will notice some very obvious problems with the surface layout. With this foresight about what is required for manufacturing you will be able to go back and rework your surfaces appropriately.

Another thing you could try is building a new surface that is appropriately grided that can be defined as the drive surface. The drive geometry does not have to be the surface of your part. You can have some other surface with a similar, but simpler, shape that mimics the flow of the part. The tool path is generated by tracing the drive surface and then projecting onto the part surface along the defined projection vector (usually use "Normal to Drive" for something like this, but others will work). If you have a "Cut Area" selected that will also be considered. Using a separate drive surface like this is more time consuming, because you need to model it, but allows you to cut virtually anything regardless of how the original surfaces are structured.

Streamline essentially creates this extra drive surface for you in a very automated way and works pretty darn well for stuff like this.

NX 7.5.4, NX 8.0.1.5
Tecnomatix Quality 8.0.1.3
PC-DMIS 2011 MR1

 

[sebw]

Dear DaSalo,

Thanks for that explanation! I think this is the way to go!

I managed already to get the desired toolpath for the center of the board -I am only missing the tail and nose- by breacking up the surface into an even grid - But I feel I am very close now.

Thank you so much and I will let you know once I have it completly worked out.

Like you say, it comes down to the grid and selection. Same in NX2.

 

[sebw]

Hi DaSalo,

as always, once you have one problem solved, the next on comes up straight away...

I got the toolpath going 95% now, but the problem is, that once the disc passes the wide point of the board it keeps cutting with the front and the back actually goes to deep in the board...

I uploaded a screenshot for better understanding.

Is there a way to prevent that ?

 

[sebw]

Problem solved ! Choosing the tool to be a T-cutter made it work...

 

[DaSalo]

It won't gouge if you select the entire surface of the board as your "Part" geometry. Then you set the tolerances in Cutting Parameters => Stock. There is also a box in the "Surface Area" dialogue that allows you to choose the behavior when gouging. Set it to "Warning" or "Retract". This will significantly increase the amount of time it takes for path generation so be prepared. You are working with a bit of an odd tool so will need to get creative to get this to work out as you hope. I'm sure it is possible but you might need to play with it for a bit to figure out the different a settings.

Why can't you just finish one side down to the mold line with a ball endmill, flip it into a nest, and then finish the other side down to the mold line?

Get yourself a good vaccuum table, mill a nest from some stacked up MDF, put in a few locating stops if necessary, and your good to go.

NX 7.5.4, NX 8.0.1.5
Tecnomatix Quality 8.0.1.3
PC-DMIS 2011 MR1

 

[sebw]

Using the T-cutter actually seems to work very easy.

Please see attached screenshot.

The problem with the machining is that these are standard machines to cut surfboards...and I can not midify the settings, as it is not my machine.

My own machine has a ball end mill and we have no problem. But I am in Portugal and the board needs to be cut in Australia.

Anyway, all good now...just need to work ou the last details in nose and tail and I am good.

Thanks again for the amazing help here !

 

[sebw]

Here the screenshot...

 

[DaSalo]

Cool, glad you got it working! Once you get the hang of "Surface Area" the sky's the limit. You can cut anything with that method if you take the time to set it up correctly and you understand exactly what information the software needs.

Can you post a photo of a finished board?

NX 7.5.4, NX 8.0.1.5
Tecnomatix Quality 8.0.1.3
PC-DMIS 2011 MR1

 

[DaSalo]

Oh, one thing I will add. If you haven't discovered it already you might want to look into the option in the Surface Area dialogue that allows to you define the percentages of the drive surface that you want to use. I'm at home now and can't remember exactly what the option is called. There is a way to either truncate or extend, both along and across the cut direction, the drive geometry. This might help you to get out to your nose and tail. This is how I got the path to cut the tail nicely in the images that I sent. I only specifically defined a drive surface up to the point where I added in those extra face divisions near the tail and then set the percentage of the drive surface to 110% in that direction. This effectively extends the drive surface. As long as the part does not change shape radically in this extension area you will generally still get a very good, clean path. You can also use a negative percentage to extend from the opposite end. Hopefully this option is available in NX2, it is very useful for fine tuning the path and for blending one operation into another.

When you get some spare time I would still look into creating a completely separate drive surface. I think that will ultimately be the way to go so you can be totally free with your design and still have confidence that you will be able to quickly generate the toolpath. If you get a good, generic drive surface worked out, maybe something that will scale parametrically with your part through expressions, you will likely be able to create a nice template that will allow you to cut any board that doesn't radically deviate from this shape without any modifications to your CAM operations at all. Then you can just design all day and kick out the toolpaths as an afterthought. This is where NX really gets cool and everything else gets left in the dust.

NX 7.5.4, NX 8.0.1.5
Tecnomatix Quality 8.0.1.3
PC-DMIS 2011 MR1

 

[sebw]

Hi DaSalo,

a BIG Thank you for all your help! I would not have made it without your support. We have cut the first board today and the result is great.

I attach you a first picture. The shape is actually a little different to what I have uploaded before. It's a 12'6'' Stand Up Paddle board...

 

[DaSalo]

Congratulations! I'm very glad that worked out for you. Thanks for uploading the pic.

Any tips that you can share about how you were able to refine the path to get exactly what you needed?

NX 7.5.4, NX 8.0.1.5
Tecnomatix Quality 8.0.1.3
PC-DMIS 2011 MR1

 

[sebw]

Hi DaSalo,

just coming back to how I did it.

I actually followed your advice and designed the surfaces / grid in way that it was selectable.

So the drive geometry and the surfaceds to be cut were the same.

But I also understood how I could use this new geometry to cut a surface that maybe not identical to the drive geometry.

Again a big thank you, we have been cutting more boards already in Australia and it just works perfect.

 

[plancton]

Hi all, i am Surfboards Shaper, and i would like to know if the NX8 it works fine to generate the tool paths for the surfboards, im traiyng work with this software but i never get the toolpaths, Someone know how its do?

i work with the shape 3d or board cad to draw the surfboard, because its mor simple and fast, i export this shape with step extension , i import to the NX8 and now someone can help me how can i do the rest?

Best regards